• ### Where are they now?

Uses make-to-ten strategy to mentally add single digit numbers and beyond ( eg, 8 and 6, 18 and 6) Solves 2 digit addition problems with support , eg model 28 + 36 using MAB, 10 frames or Open Number Lines

• ### Where to next?

Uses number fact knowledge and renaming (grouping) to record solutions to problems involving 2 digit numbers

Uses number fact knowledge to solve single digit, multiple addend problems

• ### Where are they now?

Uses make-back-to-ten, halving and/or place-value-based strategies to mentally subtract single digit numbers from 1 and 2-digit numbers
Solves 2 digit subtraction problems with support (eg, MAB and Open Number Lines)

• ### Where to next?

Uses number fact knowledge and renaming (trading) to record solutions to subtraction problems involving 2 digit numbers

May use MAB initially

• ### Purpose

Addition and subtraction are an important part of the skill set of a numerate person and are foundational skills for the other operations (multiplication and division) as well as for the larger body of mathematics.

• ### Building Addition and Subtraction skills:

#### Resources Notes

Many of these activities are the same as those in the Part-Part-Whole section as the core concepts are identical. There is an added emphasis her on connecting these ideas to the language of addition and subtraction however.

### Activities and Assessments

Race past 90 and Back (supplemented)

Focus: Adding and subtracting two digit numbers to and from two-digit numbers with support (modified hundred chart) leading to written methods.

Race past 90 and Back game board

Bees template

Spinner 0-9

Spinner 0-30

Race past 90 and Back

Focus: Mentally keeping a progressive total of a series of single digit numbers.

How: See Card Flip Addition instructions

Card Flip Addition score

Numeral Cards 1-9

120 Straw subtract (supplemented)

Focus: Subtracting 2 digit numbers from 2 digit numbers with support (bundled straws) leading to written methods.

100 Straw Subtract score sheet

Bees template

Spinner 0-30

Spinner 0-9

Grab 100 (supplemented)

Focus: Subtracting 2 digit numbers from 2 digit numbers with support (bundled straws) leading to written methods.

How: See Grab 100 instructions

Grab 100 score sheet

Long Walk, Short Pier (supplemented)

Focus: Adding and subtracting 1 and 2 digit numbers to and from 2 digit numbers with support (number lines) leading to written methods .

Long Walk, Short Pier game board

Long Walk, Short Pier markers

Spinner +/-

Spinner 0-20

Spinner 0-9

Draw Five – Difference Bingo

Focus: Subtracting 2 digit numbers from 2 digit numbers, practicing written and mental methods.

Draw Five – Difference Bingo score sheet